Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — ZIP/21203

21203

ZIP 21203 is in Baltimore, Maryland, in Baltimore City; area codes 410, 443 and 667; Eastern time. Baltimore has 42 ZIP codes in all.

Type
No street area
Time zone
America/New_York
Coordinates
39.2847, -76.6205

The Census map gives this ZIP code no delivery area of its own, which usually means it serves post office boxes, a single organization or a post office rather than streets of homes.

This ZIP code has no Census tabulation area of its own. Its point falls inside ZCTA 21201, whose figures describe that area — not this ZIP code.

☼ Live from 21203 — Baltimore, MD

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Local time: —

Where 21203 is

This ZIP code has no Census tabulation area, so there is no boundary to draw — the marker is its published point location.

★ Weird and wonderful facts about 21203
  • 🔢 Type 21203 into a pocket calculator and turn it upside down: EOZIZ — not quite a word, sorry.
  • ➕ As a number, 21,203 = 7 × 13 × 233. Its digits add up to 8, a total 251 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 101001011010011
  • 🏠 Its numerical neighbours: 21202 (Baltimore, MD, 1 mi away) and 21204 (Towson, MD, 8 mi away).
  • 🔄 Backwards, 21203 becomes 30212 — and that is a real ZIP code: Experiment, GA, 595 miles away.
  • 👥 33 other ZIP codes are made of exactly the same digits (01223, 02123, 02132, 03221, 12023, 12032, …). The farthest-flung twin is 32102 in Astor, FL, 755 miles away.
  • 🧭 Farther north than 51% of all ZIP codes, and farther east than 83%.
  • 🎯1,167 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 21203 and you would come out at 39.28°S, 103.38°E — 864 miles from Perth, Australia, the nearest big city to that spot.
  • ☀Longest day of the year: 14h 56m of daylight. Shortest: 9h 24m.
🌙 The sky over 21203 today
  • Working out the sun…
🌋 Shake report
  • Checking the USGS…

Source: USGS.

Business and tax activity

Business establishments27This ZIP27
Employees1,629This ZIP1,629
Annual payroll$100,583,000This ZIP$100,583,000

Land area

ZIP codes near 21203

ZIPCityDistance
21235 Baltimore, MD 0.0 mi
21241 Baltimore, MD 0.0 mi
21263 Baltimore, MD 0.0 mi
21264 Baltimore, MD 0.0 mi
21270 Baltimore, MD 0.0 mi
21273 Baltimore, MD 0.0 mi
21275 Baltimore, MD 0.0 mi
21278 Baltimore, MD 0.0 mi
21279 Baltimore, MD 0.0 mi
21280 Baltimore, MD 0.0 mi

Find every ZIP code within 10 miles of 21203 →

Questions about this ZIP code

Where is ZIP code 21203?

21203 is in Baltimore, Maryland, in Baltimore city, part of the Baltimore-Columbia-Towson, MD metropolitan area. Its published point location is 39.2847, -76.6205.

What county is 21203 in?

21203 lies in Baltimore city.

What area code is 21203?

Baltimore uses area codes 410, 443 and 667, from NANPA's telephone records.

What time zone is 21203 in?

21203 uses America/New_York.

What ZIP codes are near 21203?

The closest are 21235 (0 mi), 21241 (0 mi), 21263 (0 mi), 21264 (0 mi) and 21270 (0 mi).

Is 21203 a PO Box ZIP code?

Possibly. The Census map gives this ZIP code no delivery area of its own, which usually means it serves post office boxes, a single organization or a post office rather than streets of homes.

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Cite this page

zipcodes.pro. “21203 ZIP Code — Baltimore, Maryland (Baltimore City).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/21203

Machine-readable version of these facts:

curl https://zipcodes.pro/zip/21203.json

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